Summary Loranthus europaeus is an important medicinal plant, which contains a lot of bioactive compounds. The dried plant fruits were extracted in 80% methanol by maceration. Chemical detection of crud plant extracts was performed. The total flavonoids were isolated, subjected to thin layer chromatography (TLC) using different mobile systems. The purified material was augmented by using high performance liquid chromatography (HPLC). Inflammation was induced in experimental animals (rabbits) by subcutaneous injection of 2.5% formalin. The anti-inflammatory effect of the extract was evaluated in healing skin wounds in comparison with the synthetic pharmaceutical medication Piroxicalm Gel. Simple preparation was applied by mixing the crude compound with Vaseline and Glycerin. After healing of the wound, histopathological study was necessary to support the results. Results indicated that, L. europaeus fruits were rich with flavonoids of the total flavonoids were estimated, the major components were rutin and lueteolin and trace of quareciten and kaempferol. The healing of the skin was clear by disappearance of odema and reduction in scar size, enhancement of fibroblast proliferation, angiogenesis, keratinization and epithelialization as compared with the control groups. L. europaeus extracts could be considered as one of the promising plants for the treated of skin wound. Flavonoids of the plant have the ability of suppression of acute inflammation induced by chemical substance and seemed to be the most active component for healing the wound. Chapter One Introduction and Literature Review 1. Introduction and Literature Review 1.1 Introduction Chemical components of the plant medicinal are the most important for pharmaceutical companies. People are interested in medicines prepared from plants due to their little side effects, cheap and almost available compared with synthetic drugs. This may be because of the low concentrations of the active compounds found in plants which the human body would need (Mackin, 1993). Arokiyaraj et al. (2007) mentioned that a large number of these plants, plant extracts, plant derivatives and/or their isolated constituents have shown beneficial biological effects: including immunomodulatory, anti-oxidant, anti- inflammatory, anti-mutagenic, anti-carcinogenic and anti-microbial effects. Modulation of immune response by using medicinal plant products has become a subject of scientific investigations; several plants have important secondary metabolites that can interfere with different immunological functions; for instance, activation of humoral and cell-mediated immune responses, which are crucial for the integrity of immune system against invading pathogens or a carcinogenic transformation. These secondary metabolites have different structures that correlate with different chemical terminologies (flavonoids, alkaloids, tannins, glycosides and others), and therefore they may have different functions with regard to their biological potentials (XD et al., 2008). Wounds are the result of injuries to the skin that disrupt the other soft tissue. Healing of wound is a complex and protracted process of tissue repair and remodeling in response to injury. Inflammation is the response of living tissue to mechanical injuries, burns, microbial infections, and other noxious stimuli that involve changes in blood flow, increased vascular permeability, activation and migration of leucocytes and the synthesis of local inflammatory mediators (Wiart, 2006). 1 Chapter One Introduction and Literature Review Various plant products have been used in treatment of wounds over the years. Wound healing herbal extracts promote blood clotting, fight infection, and accelerate the healing of wounds. A list of medicinal plants that have been investigated for the skin and skin structure protection are used for healing wounds: such as Coconut Palm; Oak Gall; Eucalyptus; Fenugreek; Onion; Black Nightshade, Cinnamon, Coffee, Digitalis (Fleming, 2002). Most earlier systematic treatments contain all mistletoe species with bisexual flowers (though some species have reversed to unisexual flowers), while most modern systematisms treatment as a monotypic genus with the only species Loranthus europaeus Jacq. The summer mistletoe or European yellow mistletoe in contrast to the well-known European or Christmas mistletoe (Viscum album L., Santalaceae or Viscaceae) is deciduous. The systematic situation of Loranthus is not entirely clear, and some showy mistletoe in Asia may be true parts of this genus (Waly et al., 2012). Aims of the Study 1) Detection the classes of active compounds present in Loranthus europaeus methanolic extract. 2) Quantitative and qualitative estimation of the total flavonoids in dried fruit Loranthus europaeus plant extract. 3) Identification of the purified flavonoids using (HPLC). 4) Histopathological study of the extract affected in healing skin wounds and inflammation in rabbits in comparison with the synthetic pharmaceutical medication. 2 Chapter One Introduction and Literature Review 1.2 Literatures Review 1.2.1 Loranthus europaeus The family Loranthaceae, is a large family that belong to the order Santalales, it includes about 75 genus belong to 1000 species, some of these species are parasites on the roots while the remaining parasites on branches and stems trees and known as Mistletoe (Waly et al., 2012). Loranthus europaeus Jacq. (Loranthaceae) is hemiparasitic mistletoe of South-Eastern Europe, Anatolia and South Russia (Balle et al., 1960). L. europaeus has a similar branching pattern to the evergreen mistletoe Viscum album L., but it is deciduous, yellow-berried mistletoe, with dull brown twigs, with flowers located in stipulate inflorescences and respectively berries (Briggs, 2009). L. europaeus grows mostly on branches of Quercus species and occasionally of chestnuts as host trees (Harvala et al., 1984). Barnhart and Steinmetz in 2008 found the alliance of oaks and mistletoes became a symbol of knowledge and strength, and it was aptly rendered in the word “Druid” (i.e. the oak-knower), which is derived from the Greek word for oak. Mistletoes on oaks have a symbolism and a healing status that is very interesting, because both species were highly prized by ancient people, all chemists and herbalists (De Cleene and Lejeune, 2003). 1.2.2 Common Names and Taxonomy (Watsonand Dallwitz, 1991) Kingdom : Plantae Subkingdom : Tracheobionta Superdivision : Spermatophyta Division : Magnoliophyta Class : Magnoliopsida 3 Chapter One Introduction and Literature Review Subclass : Rosidae Order : Santalales Family : Loranthaceae Genus : Loranthus Scientific Name: Loranthus europaeus Common Name: Mistletoe Figure (1-1) Mistletoes on oaks (Watsonand Dallwitz, 1991) 1.2.3 Plant distribution European Mistletoe is found mostly in Europe and as far as Iran, not found in America or Australia. It is grow in central Europe and China. The showy mistletoes can be found throughout the world (Watsonand Dallwitz, 1991). 1.2.4 Plant description The flowers of L. europaeus are small, green, usually have four to six parts and may be either unisexual or bisexual. Other species of a broader Loranthus have very large, showy flowers, with blooms in lively colors. Fruits are berries, usually containing a single seed, that are dispersed by birds (Watsonand Dallwitz, 1991). 4 Chapter One Introduction and Literature Review Figure (1-2): Fruits of Loranthus europaeus (Watsonand Dallwitz, 1991) 1.2.5 Active constituents of L. europaeus Generally the studies on some species of the Loranthaceae family have indicated the presence of several chemical compounds, including flavonoids and alkaloids (Fernandez et al., 1998). Lectins and viscotoxins (Park et al., 1999), arginine and polysaccharides (Sinha et al., 1999), Loranthus species are known to produce variety of bioactive compounds, like sesquiterpene lactones from Loranthus parasiticus (Okuda et al., 1987). In a study by Egbuonu and Nwankwo (2011) and Orji et al. (2012) occurrence of many other chemical components was known such as tannin, terpenoids, phenols, flavonoids, glycosides, triterpenoids and resins in L. micranthus Linn. On L. bengwensis species screening process, alkaloids, flavonoids, tannins, cardiac glycoside, terpenes and steroids were present in both aqueous and ethanolic extract. The quantitative phytochemical screening of the aqueous extract revealed that the plant contains 0.30% flavonoids (Olatunde and Dikwa, 2014). 5 Chapter One Introduction and Literature Review Preliminary chemical analysis for L. europaeus oil extract showed the presence of glycosides, carbohydrates, aldehydes and ketone, triterpenoids groups, protein and polysaccharides (Jawad et al., 2007). Qualitative analysis and thin layer chromatography (TLC) for extract of L. europaeus seed, showed the presence of: Alkaloids, Flavonoids, Saponins, Glycosides and Terpenoids (Al-Fartosy and Al-Rikaby, 2007). In the study by Hamad et al. (2013) many flavonoids were detected included: Kaempferol, Quercetin and Rutin in methanol and ethyl acetate extract. 1.2.6 Biological potentials of L. europaeus Steiner (1989) indicated historically, that the intentions of mistletoe uses were manifold and conflicting in several cases (i.e., swellings or tumors, epilepsy, hysteria, delirium, vertigo, antispasmodic, tonic and narcotic, labour-pains, weakness of the heart and edema, eczema, ulcers of the feet, burns, and granulating wounds). 1.2.6.1. Antimicrobial Activity The species Loranthus micranthus was studied for its